1. Field of the Invention
The present invention relates to a material for treating heavy metals and metal ions and, more particularly to a material of this kind that is capable of treating harmful heavy metals and metal ions contained in, for instance, various effluents such as effluents resulting from the water treatment of semiconductors, slurries and sludges are confined in their solidified state and thus prevented from elution, the treating material thus being used to render these substances non-pollutive.
2. Prior Art
Harmful heavy metals and metal ions contained in various effluents have hitherto been subjected to absorption treatment employing activated carbon or ion exchange membranes.
Among the conventional treatment methods, the use of activated carbon is disadvantageous in that activated carbon provides only a low level of absorption effect within a liquid, and is effective for a limited range of absorbable objects. In addition, since activated carbon is relatively expensive, it cannot in practice be used to treat large volumes of waste water. On the other hand, the use of ion exchange membranes, which are also expensive, is not practical, either. At present, therefore, in order to prevent the discharge of untreated effluents or slurries and sludges which have been treated but contain unabsorbed and harmful heavy metals and metal ions, to the lakes, ponds, rivers, etc., these effluents and the like are either stored within water-tight storage ponds where they are left untreated, or are discharged to the sea. In the case of storage in storage ponds, if the waterproofing structure happens to become destroyed, or if a pond overflows due to a large inflow of rainwater, there is a risk of the harmful heavy metals and metal ions flowing into lakes, ponds, rivers, etc., and even permeating into the underground strata. This may lead to destruction of the living environment. In the case of discharge to the sea, this would of course lead to marine pollution For the above-described reasons, it is strongly desired that heavy metals and metal ions should be treated in such a manner as to be securely confined in their solidified state and thus prevented from elution.